Rain water harvesting and slow sand water filters

In September of last year a 5 gallon slow sand filter (filter 10a)  was set up. The orginal post is here. Since then 2 more filters have been added to the experiment. We call them filter 10b and 10c. They have been running for about 4 months, however this winter has been very cold and all the filters here were frozen solid for nearly 45 days total. The first flow rate test this year was just done today. No dependable tests could be done in January, or February because the temps were below freezing too often.

The flow rate chart for filter 10a (from last years post) is here:

flow rates for filter 10b and 10c:
:

If you “backwash” a slow sand filter, you will destroy it.  Backwashing is for rapid sand filters. I posted a bit of info on this about a year ago. I did not mention why backwashing will ruin a slow sand filter. Here is why:

A slow sand filter works by allowing layers of living microscopic organisms to actually grow in the sand. As water flows down through the sand, these organisms form layers, the most dense being on the top. There are layers further down in the sand that never need to be disturbed when the filter is “cleaned”. Also, most slow sand filters use a layer of gravel at the bottom to prevent the sand from clogging up the drainage pipes. Backwashing (forcing water back up through the bottom of the filter) will mix the sand and gravel, and mix the biological layers. This will destroy the filters effectiveness and ruin it. Don’t backwash a slow sand filter.

It is now February 7, 2014. At this location its been below freezing at night for all of February, and for the past 4 days not above freezing at all. On the 6th of Feb. at about 4:00 am, the low here was 13.5 degrees F (-10 deg C).  All of the filters are frozen solid with the exception of the larger filters 2 and 3. They are being fed with water from the shallow well that is heated by the un-frozen ground here and the pump house has a very small heater to keep the pump from freezing; the water must run continuously or it will freeze in a few minutes at 14 degrees F.  All of the ponds are frozen. It will likely be at least another week before we can continue running water through the filters, and then at least another 3 weeks until we can do another test.  Probably the first part of March at the earliest, weather permitting.

Water is becoming an issue here in the U.S. for a number of reasons :

http://www.marketwatch.com/story/us-drought-hurts-cattle-crops-prices-heat-up-2014-02-07

http://www.opb.org/news/article/council-recommends-drought-declaration-for-4-ore-counties/

http://bigislandnow.com/2014/01/16/big-isle-drought-declaration-triggers-usda-loan-assistance/

http://www.usda.gov/wps/portal/usda/usdahome?contentidonly=true&contentid=drought_news.html

Rain water harvesting is a way to store water. Even if it is only used for non-potable purposes, it still helps save potable water. A 1500 square foot roof can catch 3700 gallons of water from 5 inches of rain (allowing 20 percent loss due to evaporation, first flow diversion, and non-smooth roof surfaces). There are 231 cubic inches per gallon.  A 1500 square foot roof has  1500 X 144 = 216000 square inches of surface. Five inches of rain on a 216000 square inch surface is 1080000 cubic inches. Divide that by 231 and you have 4675 gallons of water. Take away 20 percent of that due to surface conditions, evaporation, and needed first flow diversion and you have 4675 – 935 = 3740 gallons. divide that by 5 = 748 gallons from 1 inch of rain. add another 20 percent loss and you have 600 (598.4)  gallons. You can wash a lot of clothes with 600 gallons of water. Think about it. Its not against state law to set up a few rain barrels. Check out the rest of this blog and its accompanying websites for lots of info. 

The runoff from the average house with 6 downspouts could easily fill 6 55 gallon rain barrels from just 1 inch of rain. A slow sand water filter, combined with a first flow diverter, will purify the water so it can be used without the danger of serious contamination.

This is an update from a previous post that has become so huge I will have to do something, not sure what yet. Anyway, here is the info on Ohio:

Update, February 1, 2014 regarding Ohio:

After checking the Ohio gov’t website, I found nothing stating that rain water harvesting (setting up rain barrels) is against the law. It is encouraged. See see the numerous links that follow:

A rain barrel store in Westlake Ohio sells rain barrels

A rain barrel store in Lima, Ohio sells them

This link lists partnering communities in a rain water harvesting related effort where rain barrels are encouraged

Clermont county, Ohio recommends rain barrels

The city of Cleveland, Ohio recommends rain barrels

The Ohio EPA recommends and funds rain barrels

Ohio has lots of rules about  water. Be sure to read up before you start your rainwater harvesting project. It is highly likely that its not against the law to harvest rain water in Ohio, but watch the regulations and read the definitions.

There are places in the US where water is rapidly becoming an issue. California is in the midst of a severe drought. In other places, there are problems with water polluted from hydraulic fracturing  otherwise known as “fracking” and chemical spills. For some people, rain water harvesting (roof water harvesting) may be a viable solution to water shortages. If your’re on a well and it goes dry you’ve got a real problem. If your drinking water gets polluted, you’ve got a problem. Check the pages of this blog for some suggestions on how to harvest water from the surface of your roof. Contrary to some people’s media caused fear, it is not against the law (with only a few exceptions) for individuals to harvest small amounts (under 10,000 gallons per day) of rain water for personal use. 

The weather has warmed up here. For the past 2 weeks it has been above freezing most of the time. The 5 gallon filters have been running for 2 weeks. The output on all;  10a, 10b, and 10c; has cleared up considerably. If the above freezing weather holds for another 2 weeks, we will do another test on the outputs of each.

Jan. 10, 2014 post filter water

Jan 10, 2014 pre-filter water

October 14, 2013 post filter water

October 14, 2013 pre-filter water

Although the outputs have cleared up, and it looks as though these small shallow filters may work in a somewhat limited fashion, it must be realized that the flow rate on these filters is very, very, very slow. Much like a dripping faucet. They will not function at all with a rapid flow. Do not confuse these filters with the type of device you might see used with pressurized water from a kitchen faucet, or filtered water that flows from a refrigerator dispenser. You can’t just pour water in a slow sand filter and have it come “flowing” out magically cleaned and pure to fill a glass in just a few seconds. We are talking 3 or 4 hours here to provide even one gallon of water.  Please see the extensive post we have on these small filters for more information. We have been working with these 5 gallon filters for nearly 4 months now, and with larger versions for 7 and a half years. There is a tremendous amount of information.

Update December 8, 2013: The temperature got down to 10 degrees F here last night – this was the last measurement we had, it is likely that the temp was lower than that (we are not actually in Seattle, we are way out east and north of the city in the Cascade mountain foothills of northwest Washington state). For a while there was a breeze which put the wind chill below zero for sure. This was unusually cold weather. All of the filters that were running here, including filter 2 and 3, are frozen solid and major damage is expected. It may well be several months before anything can be done, and will likely be the middle of March, 2014 before any of the filters will be producing filtered water output. This cold was a surprise; we did not expect the temps to go this low. The pipes on filter 2 and 3 were wrapped and the pump had a heater, so the water flowing through the system was warmed. This did not help, the filters still froze. When I checked, it looked as if the top surface of the water freezing over caused the float valves to malfunction, which then disrupted the flow of warmed water through the filter. That was the beginning of the end. Once the water stopped flowing everything except the pump froze solid. (The pump and pressure tank were in a heated enclosure) Now most of the pipes will be cracked and the filters will need to be emptied, and new output pipes installed. This is a major setback, and a major learning experience. Temperatures at or below 20 degrees F for more than several days will ruin one of these filters, unless they are kept above 32 degrees F and water flows through them continuously.

It is December 6, 2013 and all the filters here are now frozen, with the exception of filter 2 and 3. It is unsure if they will last much longer. The temp. has been below freezing at night for the past week; and barely 32 degrees F during the daytime. The temp. did not get above 28 deg F here today. Now the conditions are windy here and, and the forecast is for colder weather for the next 3 days. I do not know when the filters will start again; probably not until sometime early next year in January, if we are lucky. After they start, it will take at least 3 weeks until they are working. It is likely to be sometime in February before any more testing is done.

Update; March 21, 2014:

We have found that nearly every state in the U.S. allows rain water harvesting by individual home owners. Only a few states have severe restrictions. This could all change if citizens do not stay involved in government business. Anyone with enough money and influence can cause laws to be changed. Hopefully , the information on this blog will help people keep themselves informed with the truth about what is going on in their state governments. If rain water harvesting really did become illegal, as some people want to make it seem,  it would be catastrophic; but for now that is only a looming threat. Let’s keep it that way, in fact, if all states had a law like Texas, we would not have such a looming threat. (Texas has a law that actually makes it illegal to prevent anyone from harvesting rain water.)

We have been researching this intensely since February of 2013. So far after spending over 150 hours actually looking through the state government websites of 48 states, and looking at the research of others on all 50 states in the U.S. it has become obvious that Colorado is the only state where the practice of roof water harvesting, rain water harvesting or rain barrel use is illegal according to state government for some people. Colorado is  has strict regulations that are changing (some people in Colorado are forbidden by law from collecting rain water- those without a well, or water rights), and Ohio has strict regulations. Otherwise we have not found any other state government that makes rain water harvesting by individuals against the law for all citizens in all cases.

On the 48 websites we looked at, we did find that there are nearly incomprehensible regulations on water sources other than rain in most states.  We also have found that any homeowners’ association, any county, or any city may have laws in addition to state laws regarding rain water harvesting (with the exception of Texas, where the right to harvest rain water is guaranteed by law.)

This blog, and the websites associated with it are an ongoing study of slow sand water filtration, which is a sustainable technology. In view of current events and the general decline of the quality of our environment on a local and global scale; access to safe clean water through locally sustainable technology should be a top priority.

A slow sand water filter can be built from mostly recycled materials, and does not need electricity or petroleum produced energy to operate. Slow sand filters do not need  chemicals added to enable their functionality. Slow sand filters last years and are readily repaired and maintained without the need of non-sustainable resources.  Slow sand water filtration uses naturally occurring biological, and mechanical processes to remove harmful substances from water.

Sustainability is very well described here. Read about sustainability, read about slow sand water filtration; and then make your own decision about how “sustainable” rapid sand filtration, membrane filtration, or distillation really is after reading about those processes also. Look at the component parts used, energy used, and chemicals used and figure out what kind of resources are necessary in each situation.

When deciding if a water filter is sustainable technology, carefully consider:

The renewable, or non-renewable energy source required to produce the device and the pollution created when producing the device.  Is the device recyclable? What resources are used to produce the device? Are those resources renewable? Are people exploited in order to produce the device? How long will the device last? Can the device be repaired locally?Also, consider the same things when investigating the operation of the device. Water is needed by people all the time. If non-sustainable energy is needed always to run the filter, then is it really sustainable technology – even if it is produced in a sustainable manner?

What if there was a water filter that required some energy input to produce (energy that could be renewable energy), but required no resources to operate other than sunlight, gravity and some manual labor (adding water occasionally by hand). And what if this filter was totally reusable, non polluting, locally repairable, and did not wear out? That describes a small slow sand water filter. Think about it.